Weighted average method for CO Attainment and PO Attainment

Sample calculation for CO attainment using Average Student Attainment Level

1. Importance of an objective definition of CO attainment

An objective method for assessment of COs is essential to implement the OBE for continuous quality improvement. The method proposed, and used herein, is an improved form of setting the threshold and targets. Instead of defining the attainment levels in terms of thresholds and targets, a more objective definition of attainment is adopted based on Weighted Average of Student Attainment Levels (SAL). While the threshold-target method involves placing the students’ performance in two bands (below the threshold and above the threshold), the present method of using SAL uses five bands (0-20%, 20-40%, 40-60%, 60-80%,80-100%). The former method is subjective due to the arbitrariness in selecting the threshold and target, while the latter method is objective. In addition, the method is precise, simple-to-understand, and aminable to adopting a continuous improvement strategy.

2. Mathematical formulation

For the proposed objective measure of CO attainment, the average of the student attainment levels is taken as the CO attainment, where student attainment level in a CO-i will be, 3 if it is between 80-100%, 2 if it is between 60-80%, 1 if it is between 40-60%, 0.5 if it is between 20-40% and 0 if is between 0-20% .

Mathematically

Table 1 Student attainment level (SAL) or weightage

Student Performance Levels (j)	(SAL) Student attainment level wj
0-20%	0
20-40%	0.5
40-60%	1.0
60-80%	2.0
80-100%	3.0

As per this definition of CO attainment, if all the students get an attainment level of 3.0 (i.e all the students perform at 80-100% level) in questions of a CO-i, then the CO-i attainment will be 3. So, an attainment of 3 is very high. Similarily, an attainment value of 2 means that all the students performed above 60%. It can also be obtained when some students may perform below 60%, but that number is compensated by those who have overperformed (beyond 80%). For example, a CO attainment of 2 can be obtained when 50% students get 40-60% marks in that CO, but remaining 50% have performed in 80-100% range.

Fig.  2.1 CO Attainment by averaging student attainment levels

3. Comparison with Threshold-Target method

The principal features and advantages of the method are summarised below

·         It is based on the % of students in various levels of performance (0-20%-40%-60%-80%-100%) in a given CO

·         Based on the number of students in each attainment level, a decimal number is generated. 

·         This CO attainment value is precise

·         This CO attainment value is a function of attainment levels which will remain same across all COs, courses and programmes

·         The attainment value has an absolute meaning. For example a value of 2.2 means that  most of the students crossed the 60% mark and very few crossed the 80% mark

·         The target for the next AY can be set based on previous years CO attainment value

·         In the threshold-target method, highest CO attainment is obtained when the percentage of students crossing the ‘set threshold’ value is equal to or more than the ‘set target’ value. In the modified or improved method, the highest CO attainment value of 3 can only be achieved when 100% of the students cross 80% marks in the CO under consideration. This being a very high performance level, can give a long-term target, and a clear scope for continuous improvement.

 

Fig.  3.1 Comparision of the Attainment measures

4. Implementation of the method

For computing the attainment of course outcomes using direct attainment method, the following steps are followed through institute OBE software (Contineo)

4.1 Setting of question paper pattern:

This involves describing each question and its sub-questions. The description involves the setting the ‘Label’ of the question, its maximum marks, its (Bloom’s) Taxonomy Level, the COs mapped to that question, and the POs mapped to that question. The CO-mapping of each question is, thus, collected. A question can be mapped to multiple COs also.

Fig.  4.1 Setting of question paper pattern and mappings to outcomes

4.2 Student performance:

After the evaluation of the students’ answer scripts, the question-wise marks obtained by each student is entered through the software user interface. This is done for each assessment separately.

4.3 Data Summary:

After the entire CIE & SEE assessments are completed, the following information is downloaded from the software for each course

o   CO-PO mapping

o   Question-CO mapping

o   Question wise marks of each student

          The data is downloaded in the following form

Fig.  4.2 Assessment data collected from software for one course (Geotechnical Engineering-2, 6RCV02- AY 2012-22)

4.4 Data transformation:

The data is transformed into a Quadrant format that is easy for attainment calculation. This transformed format is given in Table 2. This data contains the CO-PO mapping in the first quadrant (top-right corner), the question-CO mapping in the second quadrant (top-left corner) and the questionwise marks of each student in the third quadrant (i.t bottom-left corner)

Table 2 Transformed data for outcome calculation

4.5 Question-wise performance:

The question-wise performance of ten students is shown in Table 3. The question-CO mapping is also shown in the same table.

Table 3 Question-wise performance of ten students in 6RCV02

4.6 CO-wise performance of a student:

For getting the performance in a CO, the questionwise performance in each type of assessment is multiplied with the question-CO mapping of that CO.  The marks obtained by each student in CO-x is obtained which is referred to as MO. Similarly, the maximum marks for CO-x questions is added to get the maximum known as MM. The ratio of MO to MM is referred to as GP or Grade Point. Based on the GP, the SAL is determined using Table 1. A sample calculation for transforming question wise performance into CO-5 performance is shown Table 4.

Table 4 Performance in questions mapped to CO-5(Note: Q. No 1 is from CIE and Q. No 7,8 are from SEE)

Ten students and their performance in three questions (shown as 1,7,8) are shown in the table. These are the three questions which are mapped to CO-5, as per Table 3. Student with USN 1SI21CV403, got 4 marks in Q1, 14 marks in Q7, and 0 marks in Q8. So, marks obtained (MO) in Q1 is 4, and maximum marks (MM) of this question is 4. This makes the GP in Q1 as 4/4=1.0. Similarily, the ratio of MO/MM in Q7 is 14/ 20=0.7. From the question paper pattern (top portion of Table 3), it can be seen that there is an internal choice between Q7 and Q8 . Q7 & Q8 fall under same Group2 ( SEE, Group1=1, Group2=4). Here nQC=1, which means  that the number of questions that are compulsory is only ONE. So, the MM for this question group is 20. Thus, the GP for this question group is 0.7. So, this students (1SI21CV403) got GP of 1.0 in CIE and 0.7 in SEE. The Aggregate GP is obtained by taking simple average of these two attainments, which will be 0.85=86%. Since, this performance is in the band of 80-100%, the attainmen level of this student is 3. Note that if the weighted average of the student performance were to be taken, we get (4+14)/(4+20)=0.75=75%. This gives an attainment level of 2 for the same student. As per the policy, equal weigtage is awarded to performance in CIE and SEE.

4.7 CO-attainment:

The attainment of the CO-x is the weighted average of the performance levels of students on scale-3, or the average of the Student Attainment Values (SAL In Fig.  4.4, the CO attainment values of seven COs of a course are shown. It can be observed that for CO1, the attainment value is 0.89 because there are 3 students who got GP between 0 to 20% (0.2), 31 students who got between 20%-40%, 23 students who got between 40%-60%, 7 students who got between 60%-80% and 2 students who got GP value between 80%-100%. The formula is as follows

Fig.  4.5 CO-attainment values for seven COs of 6RCV02 during AY 2021-22

The above procedure is for calculating the CO attainment from all assessments.The same procedure is followed for measuring the attainment of Course outcomes in each assessment separately (i.e CIE and SEE). It can be noted that the weigtages for CO attainment through CIE and CO attainment through SEE are taken equal.